Photographic developing apparatus



Sept. 20, 1966 w. LIMBERGER PHOTOGRAPHIC DEVELOPING APPARATUS 5 Sheets-Sheet 1 Filed March 25, 1964 Juven/ar: WALTER LIMBERGER Sept. 20, 1966 w. LIMBERGER PHOTOGRAPHIC DEVELOPING APPARATUS 5 Sheets-Sheet 2 Filed March 25, 1964 Fig. 2

1 n H Ln H Jn van/0r. WALTER L/MBER GER I LAGENT.

Sept. 20, 1966 w. LIMBERGER 3,273,435

PHOTOGRAPHIC DEVELOPING APPARATUS Filed March 25, 1964 3 Sheets-Sheet 3 Jn ven for WALTER LIMBERGER United States Patent 9 Claims. ((11. 95-89) The invention relates to a surface developing apparatus for exposed photographic emulsion carriers which are moistened on the emulsion side to effect development as they are led to a liquid meniscus which the emulsion side faces, in which associated guide members are provided for conveying the emulsion carriers to the meniscus and a constant level liquid reservoir is provided for adjusting the meniscus, the reservoir having an outlet extending below the level of the meniscus and terminating at the bottom of a supply container for the constant level liquid reservoir, and a short pipe which terminates outside the supply container and projects downwardly to the level desired for the meniscus.

In such surface developing devices there is sufiicient liquid in the reservoir. This liquid is supplemented from the supply container only in proportion to quantitative consumption. In such liquid-developer devices, however, the consumption of the developing liquid is qualitative. By keeping available a supply of developing liquid for a considerable time, this qualitative consumption is allowed for by the developing liquid being mixed altogether. For this purpose, known pump installations have the disadvantage that during pumping all the liquid is subjected to eddy'ing such that considerable air enrichment occurs and the free air intake leads to oxidation which reduced the efficiency of the liquid.

In order to overcome the disadvantage of oxidation of liquid which is stored in a tank over a long period, it is already known with standard treatment baths to allow .thebath liquid to flow back into a reserve tank after on operation has been carried out and to reintroduce the liquid into the bath at the start of a new operation. This results in thorough intermixing of the liquid available, but adjustment of quantitative decreases in the amounts of fluid is out of the question. It is necessary to take into consideration, in this connection, that some of the developing liquid is removed with the copying material undergoing treatment so that the quantitative decrease in the amount of fluid is an important factor. This is particularly so when nioistening the surface of a photographic emulsion carrier, since it is essential for the meniscus to be held at a constant height, which is not guaranteed by connecting a reserve tank with a bath.

The invention is based on the problem of providing a surface developing apparatus which provides the advantage of circulation of the developing liquid but avoids gradual oxidation.

A further object of the invention is to provide such an apparatus in which quantitative consumption of the developing liquid during developing is automatically compensated.

A further object of the invention is to provide an apparatus which overcomes the disadvantages of the known devices described above.

The problem upon which the invention is based is overcome in that the supply container of the constant level reservoir and the bath are connected with a known reserve tank for developing liquid which can be emptied or filled as desired, which is preferably compressible and from which both the bath and the supply container of the constant level reservoir are supplied. By connecting 'ice both the supply container and the bath with the reserve tank, it is possible to fill or empty either one of them for controlling the meniscus without producing eddies in the flow.

According to the preferred embodiment, the reserve tank is connected with the supply container by a connecting pipe having a relatively large diameter, and a special connecting pipe with a greatly decreased crosssection is provided between the deepest part of the 'bath and the reserve tank. This dimensional relationship is important in order to ensure that the supply container is filled to the desired level before, or at least at the same time as, the bath is filled. This dimensional relationship is therefore surprising as in the normal way it would be assumed that filling of the bath was the first step.

According to a further particular embodiment of the invention, the volume of the reserve tank substantially corresponds with the volume of the supply container and the volume of the bath. As a result, When the reserve tank is fully compressed the meniscus in the bath is at the desired height, whilst the amount of liquid required for adjusting the meniscus is available in the supply container. For this, according to the invention, the diameter of the connecting pipe between the reserve tank and the supply container, relative to the diameter of the short pipe with the outlet and the end projecting upwardly inside the supply container and the diameter of the connection between the deepest part of the bath and the reserve tank is emptied on compression thereof when the meniscus in the bath is at the desired level.

According to a further embodiment of the invention, the reserve tank is supported between a rigid plate and a movable plate; the movable plate is moved by spring means whereby the power of the spring means is such that it is less than the power required to compress the reserve tank after the bath has been filled to the desired level. Control is thus obtained, independently of the various cross-sections, which fulfills the above mentioned conditions.

According to a further embodiment of the invention,

the supply container is arranged at least partially Within the bath and has wall members which run parallel to the wall members of the bath, at least in part, a guide member being provided beneath the bath for conveying a sheet directly under the bottom of the bath. In this way, when carrying out a copying process with a negative and a positive, the latter can be guided between a pair of gripping and transport rollers along a completely dry path until it meets the negative. In order that the invention may be readily understood, preferred embodiments therefore are described in detail below, by way of example only, in conjunction with the accompanying drawings, in which:

FIG. 1 is a diagrammatic side view in section;

FIG. 2 is a front view of an alternative embodiment, in which the upper part is a sectional view along .the line II.II of FIG 1 and only the lower part beneath the supply container is different;

FIG. 3 is a side view of an alternative embodiment of a part of the apparatus of FIG. 1.

In the drawings, only those parts essential for operation of the invention are illustrated.

FIG. 1 shows a bath 1 for receiving developing liquid. This vessel is provided with a curved bottom, which extends from an inlet end 2 to an outlet end 3 above which is arranged a pair of gripping and transport rollers 4, 5. In FIG. 1, a supporting frame 40 is shown in section. This supporting frame 40 corresponds to the supporting frame shown in *FIG. 2. This supporting frame is provided with a slot 41 for the connecting pipes.

Another supporting frame 42 (FIG. 2) is provided opposite the frame 40 on the other side of the apparatus. A base 43 extends between the two supporting frames 40 and 42. The rollers 4, 5 are positioned in the supporting frames in known manner. Driving means 43 (FIG. 2) are arranged on the spindle of one of the rollers. A belt drive 44 is provided between the rollers and the driving means provided on one of the rollers thus drives the other roller. The bath 1 is supported on lateral support members 44, 45 in the lateral walls forming the frames 40, 42. Web members 6 are arranged parallel to the line connecting the inlet and outlet ends in the base of the bath 1, on which web members a copy sheet is guided so as to pass over the bottom of the bath 1. These web members 6 can be apertured, as shown at 7, at the deepest part of the curved base of the bath 1, in order to allow adjustment of the developing liquid between the sectional bath chambers defined between the web members 6, several of which are provided parallel to one another.

A supply container 8 is provided on the frame inside the bath, the parts 9 and 10 of the container walls running parallel to the adjacent sections of the base of the bath 1 and the base 11 running parallel to the top edges of the web members 6; a space is provided for permitting passage of an emulsion carrier. The top of the supply container 8 is hermetically closed. Two apertures are provided in the base 11. A short pipe 12 projects downwardly from one opening towards the bottom of the bath 1 and terminates below the upper edge of the web members 6. The end 14 of a pipe 13 provided in the other opening terminates approximately at the height of the upper edge of the web members 6, and preferably a little above these Web members. The pipe 13 projects into the supply container 8 and terminates at 16 just below its upper wall 17. In addition, the supply container 8 is provided with a lateral opening 18 which is connected with a reserve tank 20 for developer fluid by means of a connecting pipe 19 of relatively large cross-section. The reserve tank 20 is made of a flexible material. It is positioned between a fixed plate 21, provided with an opening 22 through which the connecting pipe 19 passes, and a mounting plate 24 which is movable in the direction of the arrow 23. It will be seen that the diameter of the connecting pipe 19 is considerably greater than that of the pipes 12 and 13.

A connecting pipe 26 of relatively small crosssection is provided between the lowest part 25 of the bath 1 and the connecting pipe 19. The cross-section of the pipe 26 can be substantially the same as the cross-section of the pipes 12, 13.

A guideway is constructed parallel to the base of the bath, but spaced therefrom, by providing at least one guide member 27, which guideway serves for guiding a further sheet of material and extends from an entry point 28 beneath the inlet edge 2 to a guide member 29 beneath the nip between the pair of gripping and transport rollers 4, 5. It will be understood that the guideway can consist of a plane surface, a perforated surface, or web members, particularly web or wall members some of which are parallel to one another and the others perpendicular to one another. In the drawings, web members are indicated at 27 and the part of the wall supporting these web members at 27. The latter is advantageously arranged laterally on the side walls 40, 41 in a removable manner. The plate 21 is also secured to these side walls by means of brackets 45, 46 (FIG. 2). In addition, it can be seen that the pipes 12, 13 are provided to one side of the bath 1, outside the path of movement of a sheet of copy material (FIG. 2).

The gripping and transport rollers 4, 5 are driven in the direction indicated by the arrow by a driving motor, not shown.

The movable plate 24 is moved parallel to the plate 21 and is supported on a roller 30 which is positioned on a rocking lever 31 which rotates about a shaft 32. The shaft 32 is driven by a crank handle 33; a driving motor can be used in place of the crank handle, if desired.

The movable plate 24 is provided at its corners with upwardly extending projections 47, 48 which run in perpendicular guide members in order to prevent tilting.

Like the relationship between the cross-sections of the connecting pipes 19 and 26 and the pipes 12 and 13, the volume of the tank 20 is so chosen that, on compression of the reserve tank 20, developing liquid passes into the supply container 8 and a proportionately smaller amount simultaneously passes into the bath 1 through the pipe 26. The supply container 8 is thus filled relatively quickly and the air displaced can escape through the short pipe 13. It can be seen from FIG. 1 in particular that the opening 18 is arranged near the base 11. During filling of the supply container 8, liquid flows through the pipe 12 into the bath 1, which is simultaneously filled from below through the connecting pipe 26. If the meniscus, which rises in the bath 1 during the filling operation, reaches the opening 14 of the pipe 13, then further flow of developing liquid from the supply container 8 is prevented since air can no longer escape therefrom. Because of the volume relationship, namely the fact that the contents of the reserve tank 20 corresponds to the capacity of the supply container 8 up to the height of the opening 16 and the capacity of the bath up to the meniscus, corresponding to the level 15, this meniscus is reached exactly when the reserve tank 20 is empty. This is the starting position with a completely full supply container 8. In this connection, the larger cross-section of the connecting pipe 19 with respect to the connecting pipe 26 is of importance. If developer liquid is used, this flows through the pipe 12 from the supply container 8 so that the meniscus required in the bath 1 is automatically adjusted in known manner.

If the movable plate is retracted so that expansion of the reserve tank 20 can occur, the liquid flows through the connecting pipe 19 from the supply container and simultaneously through the connecting pipe 26 from the bath so that all the liquid is once again stored in the reserve tank 20. Advantageous mixing of all the liquid is thus achieved, without the formation of eddies.

FIG. 2 is a front view in which the same parts have the same references as in FIG. 1 and it will be seen that the pipes 13 and 12 are arranged laterally of the guideway. More detailed. description of these parts is thus unnecessary.

According to FIG. 2, the reserve tank 20 is provided as a flexible container beneath the plate 21, which corresponds to the plate in FIG. 1. The plate corresponding to the supporting plate 24 is indicated at 47 in FIG. 2. It is supported on a scissor-like member or lazyt-ongs 48 having arms which are pivoted in the centre region, rollers being provided on the ends of the arms to reduce friction. The centre pivot pin 49 is movable upwardly but not laterally in spatial relationship to the base member 43, in known manner, i.e. for example it is positioned in bearing blocks with vertical slots. In addition, a rotatable driving shaft with a handle 60 is provided in the housing. A rocking lever 51 is non-rotatably secured thereto and is connected with the upper ends of the arms by means of cables. Rotation through in the direction indicated by the arrow results in contraction of the upper ends of the arms and thus the supporting plate 47 is raised.

FIG. 3 shows a further embodiment of the invention in which the volume of the reserve tank 20 is not exactly proportional to the capacity of the supply container 8 and the bath 1. In this embodiment, the movable plate or 'wall 24 is supported on springs 34, 35 whose support 36 is constructed as a plate which can be moved up and down, for example by means of one or two rocking levers 37. The rocking lever 37 is movable by a crank handle 38 or by a motor 39 in the manner already described.

The force of the springs 34, 35 is such that the springs first force the liquid from the reserve tank 20 but are then no longer effective when the desired meniscus level is obtained in the treatment bath 1, i.e. closing of the opening 14 by the meniscus in the treatment bath prevents further liquid from passing into the container 8 if the liquid pressure at this opening 14 or at the opening 25 of the connecting pipe 6 is not to be controlled.

By means of such springs 34, 35, fluid is forced from the reserve tank 20, irrespective of the size of the latter, only in an amount required by the dimensions of the supply container 8 and necessary for obtaining the respective meniscus level in the treatment bath 1.

With reference to FIG. 1, it is apparent that the provision of the cross-sectional proportionality between the connecting pipe 19 on the one hand and the connecting pipe and the pipes 12, 13 on the other hand is an essential feature of the invention, in order to produce uniform filling of the bath 1 from the top and from below with simultaneous filling of the supply container 8.

An essential feature of the invention is the combination of a compressible reserve tank, which expands again when it is released, with a device for automatically correcting or re-setting a predetermined meniscus level in a treatment bath for wetting the surface of a copy material sheet; in a preferred embodiment of the invention, such device can be provided as a known constant level liquid reservoir.

I claim:

1. A surface-developing apparatus for exposed photographic emulsion carriers which are moistened on the emulsion side to effect development thereof by being guided past a liquid meniscus which the emulsion side faces, which apparatus comprises, in combination, a bath container for holding treatment liquid, guide members associated with said bat-h container for guiding emulsion carriers through such bath container so as to moisten the emulsion layer sides thereof, constant level liquid reservoir means for adjusting the meniscus level, a supply container for said constant level liquid reservoir means, said reservoir means being located above said bath container, first pipe means associated with said reservoir means and extending from the base of said supply container down to a position below the meniscus level in the filled bath container, second pipe means associated with said reservoir means and projecting upwardly inside the supply container and downwardly outside such container to a height which corresponds to the liquid meniscus level in the bath container, a compressible reserve tank for developer liquid, first connecting duct means between said reserve tank and the supply container, second connecting duct means between the reserve tank and a lower part of the bath container and means for compressing said reserve tank.

2. The developer apparatus of claim 1, in which said first connecting duct means comprises a first connecting pipe having a larger diameter than that of a second connecting pipe constituting said sec-0nd connecting duct means, said second connecting pipe being connected to the deepest part of the bath container.

3. The developer apparatus of claim 1, in which said first and second connecting duct means comprises first and second connecting pipes, the first connecting pipe having a greater cross-section than said second connecting pipe and said first and second pipe means.

4. The developer apparatus of claim 1, wherein the second pipe means is located upwardly in the vicinity of an upper closure wall of the supply container.

'5. The developer apparatus of claim 1, wherein the second connecting duct means communicates with said 6 first connecting duct means at its end adjacent said reserve tank.

6. The developer apparatus of claim 1, where the means for compressing said reserve tank comprise a frame, said bath container and said constant level liquid reservoir means being supported on said frame, a fixed plate secured in said frame, a movable plate adapted to be moved in a direction towards the fixed plate, the reserve tank being disposed between said fixed and movable plates, actuating means supported in said frame and adapted to move said movable plate, spring means disposed between said actuating means and said movable plate, the force of said spring means being less than the force required to compress the supply container after the bath container has been filled to the desired level.

7. The developer apparatus of claim 11, wherein the supply container is positioned at least partly within the bath container and has wall members disposed at least partly parallel to wall members of the bath container, a guidance structure being provided beneath the bath container holding the treatment liquid and including guide members adapted to guide copy sheets directly under the bottom of the bath container.

8. A surface-developing apparatus for exposed photographic emulsion carriers which are moistened on the emulsion side to effect development thereof by being guided past a liquid meniscus which the emulsion side faces, which apparatus comprises, in combination, a bath container for holding treatment liquid, guide members associated with said bath container for guiding emulsion carriers through such bath container so as to moisten the emulsion layer sides thereof, constant level liquid reservoir means for adjusting the meniscus level, a supply container for said constant level liquid resrevoir means, said reservoir means being located above said bath container, first pipe means associated with said reservoir means and extending from the base of said supply container down to a position below the meniscus level in the filled bath container, second pipe means associated with said reservoir means and projecting upwardly inside the supply container and downwardly outside such container to a height which corresponds to the liquid meniscus level in the bath container, a compressible reserve tank for developer liquid, said reserve tank having an uncompressed volume which substantially corresponds to the sum of the volume of the supply container and of the volume of the bath container, first connecting means between said reserve tank and the supply container, second connecting duct means between the reserve tank and the lower part of the bath contanier and means for compressing said reserve tank.

9. Thedeveloper apparatus of claim 8, wherein the diameter of the first connecting pipe relative to the diameters of thefirst and second pipe means and of the second connecting pipe are so dimensioned that the reserve tank is emptied on compression thereof when the meniscus is at the predetermined level in the bath.

References Cited by the Examiner UNITED STATES PATENTS 3,103,153 9/1963 Limberger 89 3,147,686 9/1964 Limberger 95-89 3,165,998 1/1965 Reick 95-89 3,203,336 8/ 1965 Limberger 9589 NORTON ANSHER, Primary Examiner. 

1. A SURFACE-DEVELOPING APPARATUS FOR EXPOSED PHOTOGRAPHIC EMULSION CARRIERS WHICH ARE MOISTENED ON THE EMULSION SIDE TO EFFECT DEVELOPMENT THEREOF BY BEING GUIDED PAST A LIQUID MENISCUS WHICH THE EMULSION SIDE FACES, WHICH APPARATUS COMPRISES, IN COMBINATION, A BATH CONTAINER FOR HOLDING TREATMENT LIQUID, GUIDE MEMBERS ASSOCIATED WITH SAID BATH CONTAINER FOR GUIDING EMULSION CARRIERS THROUGH SUCH BATH CONTAINER SO AS TO MOISTEN THE EMULSION LAYER SIDES THEREOF, CONSTANT LEVEL LIQUID RESERVOIR MEANS FOR ADJUSTING THE MENISCUS LEVEL, A SUPPLY CONTAINER FOR SAID CONSTANT LEVEL LIQUID RESERVOIR MEANS, SAID RESSERVOIR MEANS BEING LOCATED ABOVE SAID BATH CONTAINER, FIRST PIPE MEANS ASSOCIATED WITH SAID RESERVOIR MEANS AND EXTENDING FROM THE BASE OF SAID SUPPLY CONTAINER DOWN TO A POSITION BELOW THE MENISCUS LEVEL IN THE FILLED BATH CONTAINER, SECOND PIPE MEANS ASSOCIATED WITH SAID RESSERVOIR MEANS AND PROJECTING UPWARDLY INSIDE THE SUPPLY CONTAINER AND DOWNWARDLY OUTSIDE SUCH CONTAINER TO A HEIGHT WHICH CORRESPONDS TO THE LIQUID MENISCUS LEVEL IN THE BATH CONTAINER, A COMPRESSIBLE RESERVE TANK FOR DEVELOPER LIQUID, FIRST CONNECTING DUCT MEANS BETWEEN SAID RESERVE TANK AND THE SUPPLY CONTAINER, SECOND CONNECTING DUCT MEANS BETWEEN THE RESERVE TANK AND A LOWER PART OF THE BATH CONTAINER AND MEANS FOR COMPRESSING SAID RESERVE TANK. 